Skin is an essential multilayer organ. Providing a barrier against pathogens and toxins, as well as synthesizing nutrients such as vitamin D, skin is essential for maintaining an individual's physical health. The integrity of skin is also essential for maintaining one's psychological health. Skin is the most prominent part of an individual's body. Blemishes, scars, wrinkles and perceived imperfections can diminish an individual's self-confidence. Maintaining physical and psychological health, therefore, requires maintaining healthy skin.
Healthy skin comprises layers of different cells supported by a scaffolding of proteins called the extracellular matrix. The extracellular matrix supporting the skin comprises various proteins such as collagen, fibronectin and laminin. These and other structural proteins intertwine and communicate to form the structural and dynamic three-dimensional scaffolding providing skin with its strength and resilience. Cells forming the various layers of skin adhere to the extracellular matrix, and rely on both structural and biologically active signal relaying molecules within the matrix to maintain proper function. During wound healing, cells also use the extracellular matrix as a bridge to migrate into and close wounds. Providing support and pathways for healing, the extracellular matrix is an important structural and biologically active component of healthy skin. As an individual ages, however, the extracellular matrix changes and becomes weakened, leading to the appearance of wrinkles, blemishes and decreased healing.
The extracellular matrix is manufactured and maintained primarily by fibroblasts beneath the skin's surface. Manufacturing and maintaining the biological activity of the extracellular matrix, healthy fibroblasts are essential for healthy skin. Above the fibroblasts, on top of the extracellular matrix, are keratinocytes forming the epidermis. Forming the epidermis, the outer layer of skin, healthy keratinocytes are also essential for the appearance and integrity of skin. Accordingly, maintaining healthy skin from its base to its surface requires promoting the health of different cells throughout the layers of skins.